Polymers, materials, and nanomotor research at Penn State

Nanomotors in Recent Literature

Statistics based on ISI Web of Knowledge® (June 2014)

Keywords searched - nanomotor* / micromotor* /self-propulsion

Data includes articles and review papers only

Catalytically-Driven Nanomotors

Living systems are dynamic, multifunctional, and highly responsive, and they live in changing environments. Most engineered materials, in contrast, tend to be static with a single function and are suited for more predictable environments. Access to rationally-designed dynamic materials that are capable of remodeling themselves and transforming their environment will (i) minimize waste (they will change their function and purpose rather than being single-use), (ii) improve performance (they will continuously evolve their structures to optimize performance), and (iii) accomplish tasks collectively and emergently (like a colony of ants) that a single constituent element (like a single ant) cannot perform. By making these dynamic materials to be self-powered, they will also be capable of exploring and responding to their environment (sensor applications) without being tethered to a single power source or location.

We aim to create a new paradigm for molecular-level engineering of functional materials by integrating elements of the previous approaches into a unique strategy. The work will leverage (a) the precise chemical control associated with molecular-level manipulation of materials to create functional building blocks, with (b) self-propelled mobility resulting from biomimetic catalytic energy harvesting from the local environment, with (c) the rapid and reversible assembly capabilities provided by emergent processes, with (d) the intelligence and communication capabilities that have been demonstrated in groups of interacting microorganisms, with (e) the ability to perform specific tasks in response to signals from each other and the environment. Our approach is entirely synthetic and chemical, which allows us to create dynamic, intelligent materials in a way that is not impeded by the inherent constraints of biological systems.
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Polymer synthesis

One major goal of our ongoing research is the design of metal-catalyzed systems for the homo and copolymerization of functional polar vinyl monomers. Currently, both electron-rich (e. g., vinyl esters and ethers) and electron-deficient (e. g., acrylates, acrylonitrile, vinyl and vinylidene chlorides, and perfluoroalkenes) polar vinyl monomers are commercially produced by free-radical polymerization. As such, there is very little control over tacticity and molecular weight. Clearly, the discovery of general metal-catalyzed pathways for the homo and copolymerization of polar vinyl monomers would constitute a major breakthrough in polymer synthesis.

We have been the first to describe the controlled radical copolymerization of polar vinyl monomers with simple alkenes, fluoroalkenes, and norbornene derivatives. This has led to the synthesis of unique random and block copolymers. Additionally, some of the copolymers of fluoroalkenes with polar vinyl monomers form strong adherent, yet hydrophobic, coatings on a variety of surfaces.
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Materials

Bottom-up Assembly of Ordered Metamaterials: In conventional solids nature does not typically allow for much tuning of the bonding and electronic structure. Considerable interest has arisen in ordered arrays of quantum structures, such as quantum dots, that are linked together by molecules that facilitate electronic, magnetic and thermal communication. With such a metamaterial approach there is much more flexibility in designing the electronic structure by varying the linker molecules, the terminating end groups and the semiconductor quantum structures than there is for conventional solids. Our focus is on synthesis of well-ordered and structurally well-characterized 2 and 3-dimensional nanocomposite metamaterials. We have begun with an investigation of the synthesis of smaller, soluble clusters of ordered metamaterials, followed by extension of these studies to extended crystalline arrays. Read more...